Tree rings and seasonal sedimentary deposits called varves can be counted to determine absolute age.

可以对树轮和被称为纹泥季节性沉积物进行计数来确定其对龄。

The variation of varve thickness may show a decrease of sediment flux during the Little Ice Age, and an increase of sediment flux after 1960s.

但纹层厚度变化可能揭示出小冰期沉积通少和上个世纪六十代之后沉积通增加。